Cell Biology Basics Quiz

Study Notes

The thylakoid membranes of chloroplasts are folded, increasing their capacity to conduct photosynthesis.

Microtubules move chromosomes during cell division and are thicker than other components of the cytoskeleton.
Microfilaments are composed of the protein actin.
Intermediate filaments are more permanent than other cytoskeletal components.

Prokaryotic cells have DNA in a region called the nucleoid, while eukaryotic cells house their DNA in a membrane-bound nucleus.

The largest, most dense organelles, such as nuclei, will pellet first when cells are subjected to differential centrifugation.

Saturated fatty acid tails in a phospholipid bilayer decrease the membrane's fluidity, while unsaturated fatty acid tails increase fluidity.

Facilitated diffusion is a type of passive transport where a hydrophilic substance moves through a membrane channel down its concentration gradient.

The sodium-potassium pump moves two sodium ions out of the cell and three potassium ions into the cell.

Water will move from a region of high water potential to a region of low water potential.
In this scenario, the dialysis bag will swell as water moves into the bag from the beaker.

Production of transmembrane proteins: The rough endoplasmic reticulum (ER) synthesizes transmembrane proteins, which are then transported to the Golgi apparatus for further processing and packaging into transport vesicles. These vesicles then deliver the proteins to the plasma membrane.
Thylakoid Membranes: The highly folded thylakoid membranes inside chloroplasts increase the surface area for photosynthesis, allowing for greater efficiency in capturing light energy and generating ATP.

Microtubules: Microtubules are thicker than microfilaments and are essential for moving chromosomes during cell division.
Microfilaments: Microfilaments are composed of the protein actin and play a crucial role in cell shape, movement, and muscle contraction.
Intermediate Filaments: Intermediate filaments provide structural support and are more permanent than other cytoskeletal components.
Prokaryotic vs. Eukaryotic Cells: Prokaryotic cells lack a membrane-bound nucleus and other specialized organelles found in eukaryotic cells. Their DNA is located in a region called the nucleoid.

Differential Centrifugation: Larger and denser organelles, like nuclei, sediment at the bottom of the centrifuge tube first during differential centrifugation. Smaller, less dense organelles and molecules remain in suspension.
Membrane Fluidity: Unsaturated fatty acids in phospholipids create kinks, making the membrane more fluid and flexible. This allows for adaptation to fluctuating temperatures.
Facilitated Diffusion: Facilitated diffusion involves the movement of a molecule across a membrane with the aid of a membrane protein, such as a channel or carrier protein. This process is passive and does not require energy.
Sodium-Potassium Pump: This active transport mechanism moves sodium ions out of the cell and potassium ions into the cell, establishing an electrochemical gradient across the membrane. It requires energy (ATP) and operates against the concentration gradients of both ions.
Osmosis: Water moves across a semi-permeable membrane from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration).

Hypertonic: When the solution in the beaker has a higher concentration of sucrose than the solution inside the dialysis tubing, the beaker solution is hypertonic compared to the bag's solution.
Water Movement: Water will move from the beaker (high water concentration) into the dialysis tubing (low water concentration) causing the bag to swell.